Drill stem valve



W. L. PEARCE DRILL STEM VALVE ZZZZZZZ e 9 ;I:ZI,I NW N T H ON 0 6% U. A,2 c wll 0 w a igzag 3L x .:/,::I 3,

Filed March 28, .1955

July 16, 1957 M Li. \\\\mw K.

United States Patent DRILL STEM VALVE William L. Pearce, Houston, Tex.Application March 28,1955, SerialNo. 497,249

screams. (CL 137-498 This invention relates to a}d rill;stem valve,andmore particularly to a valve means which is adapted to beincorporated in a'tubular drill stem for use in the drilling ofrwellsvand which is operable by an upward flow of fluid upon ,the occurrence-fan'increase in the pressure of fluid in the stem to close the stem.

The ,invention is an improvement of the drill stem valve described andclaimed in my application, Serial No. 434,122, filed June 3, 1954.

While not limited to such use, the invention finds particularapplication in connection with the drilling of oil and gas wells,wherein a tubular drill stem is employed, anddrilling fluid iscirculated down through the stem and upwardly about the same during thedrilling operation. During;such drilling operations the .drilling fluidis forced downwardly through the stem by means of a slush pump whose;outlet is connected to the stem through a drilling hose having a swivelconnection with the upper end of the stem, and the fluid then returnsupwardly about the ex erior of the stem.

;In the .event that gas under high pressure should be encountered in thewell .in carrying-out drilling operations inIzthis manner, the pressureoffluid in the drill stem may .be suddenly increased :to an extent tocause the drilling hose "to burst'or to injure the pump valves.

The .present invention has for its chief object the overcoming of theabove disadvantages by the provision 'Of'II1'1aHS adapted to beincorporated in-a drill stem and which will beeflective upon theoccurrence-of a'sudden increase in the upward pressure of fluid in thestem to close the stern against the upward flow of fluid theretthrough.4

vAnother object of the invention is to provide a drill stem valve ofimproved construction which will remain open to permit the downward flowof drilling fluid :through the stem during the drillingoperation, butwhich is operable by upsurge of fluid in the stem due to an.

increase in the pressure therein "to close the stem against the upwardflow of fluid-therethrough.

A further objectof the invention is the provision of a drill stem valvewhich is adapted to remain in an open condition topermit downward orupward flow of fluid through the stem under normal conditions ofoperation but which is operable upon the occurrence of blow-outconditions in the well to .close the stern against an upflow of fluidtherein.

Another object of the invention is to provide a drill stern valve whichis operable solely by the pressure or fluid in the stern, which operatesupon the occurrence of an upsurge of fluid in the stem to close the stemand which is operable by the application of a downward pressure in thestem to move the valve to open position.

A further object of theinvention is the provision of a drill stern valveincluding a plunger ,movably mounted in the stern for movement to oneposition to open the valve to permit the flow of fluid through the stem.and to another position to close the stern againstsuch flow 2 andincluding seal forming means which is enclosed-and protected againstabrasion'or other injury in bothpositions of the plunger. I

Another object of the inventionis to provide a drill :stem .valve havingalcylinder mounted in the interior of the stem and about which fluid mayflow through the stem, and including a plunger movable in the cylinderand having seal .forming means enclosed in-the cylinder when the valveis in open position, the plunger being provable to a position extendingbeyond the cylinder :with'the seal forming means in sealing positionbetween the plunger and'theinterior of the stem whemthevalve is in.closed position.

A .still further object iof'the invention is the provision of 1ardrillstem valve of simple design and rugged construction, having noportion whichprotrudesbeyond'the exterior of the drill stein, and whichis capable of long withstanding :theextreme conditions of hard usage andexposure to which devices of this kind are customarily :su-bjec'ted.

flhe aboveand other important objects and advantages vof the inventionwill best be understood from "the following detailed descriptionconstituting a specification of :the same when considered in conjunctionwith the an- ;nexed drawings, wherein :Figure 1 is a vertical, central,cross-sectionalview illustrating a preferred embodiment of theinvention, and .showing'the samesconnected into a tubular drillingstring with the valve in open position;

Figure 2 is a view similar to that of-Figure 1,-showing the valve inclosingiposition; and

Figure 3 is :a vcross-sectional view taken along line .-33 of Figure 11,looking in the-direction indicated by the arrows.

*Referringlnow to'th'e drawings in greater detail, the inventioncomprises .a -tubular valve casing 10 having aan internally threaded boxiportion 12 at its upper-end :adapted to .be threadably connected to thelower externally threaded end portion 14 of an upper section 16 of atubular drilling string orstem. The casing 10 also has an internallythreaded box portion '18 at its lower :end adapted to be 'threadablyconnected to the upper ;externally:threaded 'end portion 20 of a tubularconnector which terminates at its upper end in a counterbore-32 'whoseupper end forms a beveled, downwardly facing annular shoulder 34. A bore36, which is of smaller 7 diameter than the :counterbore 32,communicates at its shoulder 46 is formed between the lower end of thebore 42 and the upper end of the bore 44. 'Thelower end of the bore 44isin communication with the upper ;end of a bore 48, which is oflarger-diameter than the bore 42 and which communicates at its lower endwith the interior of the box ,portion 18. A downwardly facing annularshoulder 50 is formed between the lower endofithe bore :44 and the upperend v0t the bore 48.

A valve chamber .30 has a peripheral wall 52 which is cylindricalthroughout a major portion of its length, and which is inclined upwardlyand radially inwardly at 54, adjacent its upper end, and is inclineddownwardly and radially inwardly at 56, adjacent its lower end. A

. cylindrical valve guide and housing member 58, which is open at itsends, is positioned in the chamber 30 in radially spaced relation to theperipheral wall 52 of the chamber 30 and in axial alignment with thecounterbore 32 and the bore 36. The cylindrical member 58 has an outsidediameter corresponding to the diameter of the bore 42, and has anenlarged lower end portion 66 which has exterior surfaces correspondingto the bores 44 and 48 and the shoulders 46 and 50 for engagementtherewith when' the cylindrical member 58 is inserted upwardly throughthe bore 42. The cylindrical member 58 may be secured in place byabutment of the lower end portion 60'against the upper end of theconnector member 22.

Within the cylindrical member 58 a plunger is movably positioned forlongitudinal movement inwardly and outwardly through the upper open endthereof to open and close the valve, as hereinafter described. The upperend of the cylindrical member 58, which is closed by the plunger, isspaced below the upper end of the chamber 30, and a plurality of ports62 are formed in the cylindrical member 58 above the lower end of thechamber and below the plunger. Thus when the valve is in its openposition, as shown in Fig. 1, drilling muds and well fluids may becaused to flow in either direction through the chamber 30, around theupper end of the cylindrical member 58 and through the ports 62.

The plunger comprises a bolt 64 which is aligned axially with thecylindrical member 58. The bolt 64 has an enlarged, pointed head 66 atits upper end and is threaded throughout its length. A pair of packingrings, numbered 68 and 70, which are formed of resilient material suchas rubber, surround the bolt 64 and are positioned one above the other.The diameter of the packing rings 68 and 70 is such that they fittightly within the cylindrical member 58, the inside diameter of whichcorresponds to the diameter of the counterbore 32. A washer 72 surroundsthe bolt 64 and is positioned between the pointed head 66 and theuppermost packing ring 68. A ring 74, which is threaded internally forengagement with the threads of the bolt 64, is applied to the bolt 64between the packing rings 68 and 70. The ring 74 is tightened on thebolt 64 sufficiently to maintain the uppermost packing ring 68 and thewasher 72 firmly in engagement with the pointed head 66. A washer 76 isapplied to the bolt 64 below the lowermost packing ring 70, and a nut 78is applied to the lower end of the bolt 64. The nut 78 is tightened onthe bolt 64 whereby the lowermost packing ring 79 is expanded so that itgrips the inner wall of the cylindrical member 58 sufficiently to resistmovement of the plunger in either direction, as hereinafter described.

The uppermost packing ring 68 is of a size to fit tight- 1y within thecounterbore 32, to form a fluid tight seal between the plunger and theinterior of the casing 10, when the valve is in closed position as seenin Figure 2. The diameter of the pointed head 66 corresponds to that ofthe bore 36, while the washer 72 is of larger diameter and has a beveledperipheral edge for engagement with the shoulder 34 to limit the upwardmovement of the plunger into the counterbore 32.

As best seen in Figure 1, the length of the plunger is such that whenthe valve is in open position the packing rings 68 and 70 are enclosedin the cylindrical member 58 and the upper end of the uppermost packingring 68 is substantially covered by the pointed head 66 and the washer72, so that the packing rings are protected against abrasion or otherdamage due to contact with the well fluid or drilling mud. When thevalve is in closed position as illustrated in Figure 2, it will be seenthat the uppermost packing ring 68 is disposed entirely within thecounterbore 32 of the casing it), while the lowermost packing ring '70remains within the cylindrical member 58, so that the packing rings areagain protected from wear or other injury due to contact with the wellfluid or drilling mud.

In making use of the invention, constructed as described above, theplunger may be positioned within the cylindrical member 58 and the nut78 may be tightened on the bolt 64 whereby the lowermost packing ring 70is expanded to such extent that it grips the inner wall of thecylindrical member 58 sufficiently to resist a predetermined pressureacting upon the plunger to move it longitudinally in either direction.The cylindrical member 58, with the plunger in place, may then beinserted in the chamber 10, through the bore 42, and the upper end ofthe connector member 22 may be threadably connected to the lower end ofthe casing 10 to complete the valve assembly. The valve then may betheadably connected to the lower end of the upper section 16, and theupper end of the lower section 28, of the drill stem.

111 this condition of the equipment, the valve is in its open position,as illustrated in Figure 1, with the plunger in its retracted position,in which the uppermost packing ring 68 is enclosed within thecylindrical member 58. It will be apparent that during the drillingoperation drilling mud may be pumped downwardly through the drillstring, passing about the upper portion of the cylindrical member 58 andthrough the ports 62, and on down through the drill string. If desiredthe drilling fluid or well fluid may be permitted to flow upwardlythrough the drilling string without moving the plunger upwardly to itsextended position, to close the valve, but upon the occurrence ofblowout conditions in the 7 well, an upsurge or sudden increase in theupward pressure of the fluid in the string will cause the plunger tomove upwardly out of the cylindrical member 58 to the closed positionillustrated in Figure 2, wherein the uppermost packing ring 68 extendsinto the counterbore 32 of the casing 10 while the lowermost packingring 70 remains in sealing contact with the interior of the cylindricalmember 58. In this position of the plunger the washer 72 will engage theshoulder 34 to limit the upward movement of the plunger, while the ring74 will close the lower end of the counterbore 32 and the upper end ofthe cylindrical member 58 to maintain the packing rings 68 and 70 out ofcontact with the well fluid below.

It will be seen that the packing rings 68 and 70 are maintained in aprotected position, in either position of the valve, to effectivelyprevent abrasion or other injury thereto due to contact with thedrilling mud or well fluid.

(The valve may be readily moved from its closed position to its openposition by pumping downwardly through the drill stem to overcome theupward pressure of the fluid beneath the valve body and the resistanceof the packing rings 68 and 70 to movement, which limitsthe downwardmovement of the plunger after it has reached the position shown in Fig.1.

The cylinder 58, the bolt 64, the washers 72 and 76, the ring 74 and thenut 78 are preferably formed of hardened, abrasion resistant material,whereby wear on these parts will be reduced to a minimum, thus assuringa long lasting structure which is economical in manufacture, and whereinthe parts are easily replaced when necessary.

It will also be apparent that the valve casing 10 and the connectormember 22 may have an external diameter substantially equal to that ofthe drill string, so that no portion of the equipment will be largerthan the drill string, thus avoiding any obstruction in the well bore.

'It will thus be seen that the invention provides a drill stem valve ofimproved construction which operates automatically to close the drillstem against the upward flow v of fluid therethrough, upon theoccurrence of blowout conditions in the well, and which is readilyoperated by '5 the application of downward fluid pressure in the drillstring to move the valve to open position when desired.

While. the invention has been disclosed herein in connection with acertain specific embodiment of the same, it will be understood that thisis intended by way of illustration only, and that numerous changes maybe made in the construction and arrangement of the various parts withoutdeparting from the spirit of the invention or the scope of the appendedclaims.

'Having thus clearly shown and described the invention, what is claimedas new and desired to secure by Letters Patent is:

1. A valve assembly comprising a tubular valve casing having aninternally enlarged portion intermediate its ends forming a valvechamber, the valve chamber terminating at its upper end in acounterbore, a cylindrical valve guide and housing member, open at itsends, positioned in the valve chamber in radially spaced relation to theperipheral wall of the chamber and an axial alignment with thecounterbore, and a plunger received within the cylindrical member andmovable from a retracted position, in which it is disposed substantiallyentirely within the cylindrical member, to an extended position in whichit is disposed partly in and in frictional engagement with thecylindrical member and partly in and in frictional engagement with thecounterbore, the upper end or the cylindrical member being closed by theplunger and being spaced below the upper end of the valve chamber andone or more ports being formed in the cylindrical member above the lowerend of the valve chamber and below the lowermost position of the plungerso that fluid may flow in either direction around the upper end of thecylindrical member, and through the ports, when the plunger is in itsretracted position.

2. A valve assembly comprising, a tubular valve casing having aninternally enlarged portion intermediate its ends forming a valvechamber, the valve chamber terminating at its upper end in a counterboreand at its lower end in a second bore aligned axially with thecounterbore, the upper end of the counterbore terminating in a thirdbore of smaller diameter and comprising the smaller of a series ofpassages communicating with the upper end of the casing, the lower endof the second bore terminating in a fourth bore of larger diameter .andcomprising the smaller of a series of passages communicating with thelower end of the casing, a cylindrical valve guide and housing member,open at its ends, positioned in the valve chamber in radially spacedrelation to the peripheral wall of the chamber and in axial alignmentwith the counterbore, the cylindrical member having an outside diametercorresponding to the diameter of the second bore and having an enlargedlower end portion for engagement with the upper end of the fourth borewhen the cylindrical member is inserted upwardly through the bore, thecylindrical member extending upwardly through the second bore and beingsecured in place by abutment of its lower end against the upper end ofthe connector member, and a plunger received within the cylindricalmember and movable from a retracted position, in which it is disposedsubstantially entirely Within the cylindrical member, to an extendedposition in which it is disposed partly in and in drictionail engagementwith the interior of the cylindrical member and partly in and infriction engagement with the interior of the counterbore, the upper endof the cylindrical member being closed by the plunger and being spacedbelow the upper end of the valve cha-m ber, and one or more ports beingformed in the cylindrical member above the lower end of the valvechamber and below the lowermost position of the plunger so that fl-uidmay flow in either direction around the upper end of the cylindricalmember, and through the ports, when the plunger is in its retractedposition.

3. In a valve assembly as described in claim 2, a plunger comprising abolt aligned axially with the cylindrical member and positioned with itshead uppermost, a pair of resilient packing rings surrounding the boltand positioned one above the other, the diameter of the packing ringsbeing such that they fit tightly within the cylindrical member or thecounterbore, depending upon the position of the valve, a washersurrounding the bolt and positioned between the head of the bolt and theuppermost packing ring, a ring threaded internally for engagement withthe threads of the bolt and positioned between the packing rings, thering being adapted to be tightened on the bolt sufiiciently to maintainthe uppermost packing ring and the washer firmly in engagement with thehead of the bolt, a washer applied to the bolt below the lowermostpacking ring, and a nut applied to the lower end of the bolt and adaptedto be tightened on the bolt whereby the lowermost packing ring isexpanded so that it grips the inner Wall of the cylindrical membersufficiently to resist a predetermined force acting upon the plunger tomove it longitudinally in either direction, the arrangement being suchthat the packing rings are fully enclosed within the cylindrical memberor the counterbore, depending upon the position of the valve.

References Cited in the file of this patent UNITED STATES PATENTS391,431 Shotf Oct. 23, 1888 1,196,926 Brown Sept. 5, 1916 1,593,519Underwood July 20, 1926 2,571,497 Stewart Oct. 16, 1951 2,675,021 AllinApr. 13, 1954

